2015
Two Na+ Sites Control Conformational Change in a Neurotransmitter Transporter Homolog*
Tavoulari S, Margheritis E, Nagarajan A, DeWitt DC, Zhang YW, Rosado E, Ravera S, Rhoades E, Forrest LR, Rudnick G. Two Na+ Sites Control Conformational Change in a Neurotransmitter Transporter Homolog*. Journal Of Biological Chemistry 2015, 291: 1456-1471. PMID: 26582198, PMCID: PMC4714228, DOI: 10.1074/jbc.m115.692012.Peer-Reviewed Original ResearchMeSH KeywordsAmino Acid SubstitutionAmino Acid Transport SystemsAquatic OrganismsBacterial ProteinsBinding SitesCysteineGram-Negative BacteriaLigandsLiposomesModels, MolecularMolecular Dynamics SimulationMutagenesis, Site-DirectedMutationPlasma Membrane Neurotransmitter Transport ProteinsProtein ConformationProtein FoldingProtein StabilityProteolipidsRecombinant ProteinsSodiumConceptsConformational changesTransmembrane helix 1Open conformational stateDependent conformational changesTransporter homologExtracellular gateProkaryotic homologCytoplasmic pathwayHelix 1Interaction networksIntermediary interactionsBiophysical assaysNeurotransmitter transportersSubstrate pathwayNa2 siteConformational statesHelix motionsLeuTDirect interactionDependent closureHomologMutantsDistinct stepsResiduesComputational analysis
2007
Interaction between lysine 102 and aspartate 338 in the insect amino acid cotransporter KAAT1
Castagna M, Soragna A, Mari S, Santacroce M, Betté S, Mandela P, Rudnick G, Peres A, Sacchi V. Interaction between lysine 102 and aspartate 338 in the insect amino acid cotransporter KAAT1. American Journal Of Physiology - Cell Physiology 2007, 293: c1286-c1295. PMID: 17626242, DOI: 10.1152/ajpcell.00190.2007.Peer-Reviewed Original ResearchMeSH KeywordsAmino Acid SequenceAmino Acid SubstitutionAmino Acid Transport Systems, NeutralAnimalsAspartic AcidBinding SitesBiological TransportCross-Linking ReagentsCysteineDithiothreitolFemaleInsect ProteinsKineticsLepidopteraLysineModels, MolecularMolecular Sequence DataOocytesPhenanthrolinesPotassiumProtein Structure, TertiarySequence Homology, Amino AcidSodiumTryptophanXenopus laevisConceptsSingle cysteine mutantsNeutral amino acid transporterSite-directed mutagenesisAmino acid transportersTransport-associated currentNSS transportersDouble mutantXenopus laevis oocytesCysteine mutantsWild typeDependent transportLysine 102MutantsSuper familyAcid transportersPermeation pathwayAmino acidsDisulfide bondsLaevis oocytesFunctional evidenceAsp338Leucine uptakeKAAT1Spatial organizationResidues
2000
Functional Role of Critical Stripe Residues in Transmembrane Span 7 of the Serotonin Transporter EFFECTS OF Na+, Li+, AND METHANETHIOSULFONATE REAGENTS*
Kamdar G, Penado K, Rudnick G, Stephan M. Functional Role of Critical Stripe Residues in Transmembrane Span 7 of the Serotonin Transporter EFFECTS OF Na+, Li+, AND METHANETHIOSULFONATE REAGENTS*. Journal Of Biological Chemistry 2000, 276: 4038-4045. PMID: 11058600, DOI: 10.1074/jbc.m008483200.Peer-Reviewed Original ResearchConceptsCys-109Methanethiosulfonate reagentsWater-filled poresNative cysteine residuesCysteine-containing mutantsExtracellular loop 1Close-contact regionThree-dimensional structureCysteine residuesTranslocation mechanismControl mutantsAlpha-helixMTSEA-biotinResidue positionsCysteine substitutionsLoop 1Conformational changesMTS reagentsFunctional roleMutantsIon bindingResiduesTransportersIon dependenceSerotonin transporter
1999
The Role of External Loop Regions in Serotonin Transport LOOP SCANNING MUTAGENESIS OF THE SEROTONIN TRANSPORTER EXTERNAL DOMAIN*
Smicun Y, Campbell S, Chen M, Gu H, Rudnick G. The Role of External Loop Regions in Serotonin Transport LOOP SCANNING MUTAGENESIS OF THE SEROTONIN TRANSPORTER EXTERNAL DOMAIN*. Journal Of Biological Chemistry 1999, 274: 36058-36064. PMID: 10593887, DOI: 10.1074/jbc.274.51.36058.Peer-Reviewed Original ResearchConceptsChimeric transportersWild type SERTExternal loop 4High affinity cocaine analogSubsequent conformational changesExternal loop regionsTransmembrane segmentsInitial binding stepScanning mutagenesisWild typeExternal loopLigand bindingSerotonin transporterMutantsConformational changesLoop 4Loop regionConformational flexibilityTransportersCorresponding sequenceBinding stepExternal domainNorepinephrine transporterActivity 5NET substrate
1998
Critical Amino Acid Residues in Transmembrane Span 7 of the Serotonin Transporter Identified by Random Mutagenesis*
Penado K, Rudnick G, Stephan M. Critical Amino Acid Residues in Transmembrane Span 7 of the Serotonin Transporter Identified by Random Mutagenesis*. Journal Of Biological Chemistry 1998, 273: 28098-28106. PMID: 9774428, DOI: 10.1074/jbc.273.43.28098.Peer-Reviewed Original ResearchMeSH KeywordsAmino Acid SequenceAnimalsBiological TransportCarrier ProteinsMembrane GlycoproteinsMembrane Transport ProteinsModels, MolecularMolecular Sequence DataMutagenesisNerve Tissue ProteinsProtein ConformationRatsSerotoninSerotonin Plasma Membrane Transport ProteinsStructure-Activity RelationshipConceptsAmino acid residuesRandom mutagenesisAcid residuesTransport activityCritical amino acid residuesRat brain serotonin transporterCritical residuesTransport cycleWild typeNonconservative mutationsStructural predictionsTransporter functionLater stepsMutationsSerotonin transporterResiduesMutagenesisHydrophobic substitutionsTyr-385TransportersMutantsActivitySubstitutionNearby positions
1997
External Cysteine Residues in the Serotonin Transporter †
Chen J, Liu-Chen S, Rudnick G. External Cysteine Residues in the Serotonin Transporter †. Biochemistry 1997, 36: 1479-1486. PMID: 9063896, DOI: 10.1021/bi962256g.Peer-Reviewed Original ResearchConceptsTransport activityMTS reagentsCysteine residuesWild typeWild-type transporterSecond external loopTransient expression systemSurface expressionRat serotonin transporterExternal cysteine residuesHydropathy analysisMutant transportersType transporterDouble mutantExpression systemMethanethiosulfonate reagentsLigand bindingSerotonin transporterMutantsExtracellular loopHeLa cellsDisulfide bondsPartial activityTransportersSerine